I purchased your GIMX Adapter and haven't had success getting proper FFB with Windows 10.
I can load the firmware and I can use my wheel to control the PS4 and drive in Gran Turismo Sport, but the wheel's FFB just feels like only the centering spring force that's working. I have unchecked combined pedal in Logitech Gaming Software.

As I had no luck with Windows, I resorted to using Raspberry Pi with automated raspbian image and it gives proper FFB so I know it's not the adapter which is at fault.

Could you please make another log file with the haptic debug flag enabled?
Select "Messages>debug", click on Start, select "log file" and validate, check "haptic" and validate.
Play a dozen of seconds and then stop GIMX.